Aldon Smith is in a safe place now, presumably receiving the help he needs to end an alcohol-abusing slide that was wrecking his life and endangering the lives of others.

He should have been working on his recovery in that rehab center Sunday, instead of inside San Francisco’s football stadium, wearing his 49ers uniform, playing a game.

And being cheered by a disturbing number of fans who got intoxicated before and during the game, then drove away in an impaired state after imbibing products from companies that spend millions courting their core audience via football.

Yes, the NFL has a drinking problem.

The fact that Smith played two days after he was arrested for DUI — again — was shameful and sad. But the rationalizations given for his presence on the field were astounding — enabling, even.

The 49ers owner said that since Smith would get a weekly paycheck anyway he might as well be playing.

Union rules citers and the usual “innocent until proven guilty” knee-jerkers said Smith had a right to play.

Then there was the fake sympathy excuse — that Smith was better off at the game, in his element, with his teammate brothers. You know, tackling, hitting, grunting, strutting, slapping helmets and releasing his aggression in a controlled, healthy environment among those who care deeply about his well-being.

Or could it be that the 49ers, ranked 27th in run defense and performing below expectations early in a losing season, just really needed their stud linebacker?

The league and its teams must show they are sincere about cracking down on troubled players. Otherwise the justifications, third chances, plea bargains and copouts reinforce the perception that the sport is a commodities market that treats its athletes like slabs of meat.

Smith is a multiple-time loser. In the latest incident, at about 7 a.m. last Friday, he drove his pickup into a tree near his home in San Jose, Calif. When found, he still had one foot on the accelerator, apparently trying to get past the tree, according to a report from the scene. His blood alcohol level was measured at .15, twice the legal limit. Marijuana was found inside the truck.

The tree could have just as easily been a car, a school bus, a pedestrian.

A drunk behind the wheel is a loaded weapon.

Smith was arrested on suspicion of drunk driving last year in Miami Beach, a charge that was reduced to reckless driving. Six months later, during a party at Smith’s house, he was stabbed by one of the members of a gang that crashed the party, say California prosecutors. Smith is being sued by two men who said they were shot in the drunken crossfire that ensued when Smith and former 49ers tight end Delanie Walker tried to break up the festive evening by firing guns.

The NFL paid its retired damaged players to make the concussion issue go away. Yet even with gargantuan profits at its disposal, the NFL hasn’t been able to stem the persistent perilous behavior of drunk players, some of whom are irresponsible, some of whom are sick. It has only gotten worse, despite enhanced team security monitoring of players. The NFLPA provides a 24-hour driving service. Therapists and life coaches are at the ready.

But players continue to receive mixed messages, like the one delivered by the 49ers. Screw up and you will be pardoned if you can perform. You’re not breaking the law if you’re above the law.

No wonder Aaron Hernandez felt he was entitled to a break when he and a friend who was driving 105 mph were pulled over by a state trooper on a Boston expressway and Hernandez said, “Trooper, I’m Aaron Hernandez — it’s OK.” What is OK? To be a speeding hazard alongside a friend who was charged with DUI? Weeks later in Miami, Hernandez allegedly shot that friend in the face. The star tight end is now being sued by that friend and is in jail facing murder charges in another case. Hernandez never learned the meaning of consequences. He was allowed to keep playing by the Florida Gators and New England Patriots despite a documented history of violent behavior and drug use.

An athlete’s bulletproof feeling is strengthened by cases such as that of Donté Stallworth, who served only 30 days for DUI manslaughter. After drinking in Miami Beach on March 14, 2009, Stallworth was driving his Bentley when he struck and killed a crane operator who was walking across the MacArthur Causeway. If Stallworth, then a Cleveland wide receiver, hadn’t been rich, he would not have reached a financial settlement with the victim’s family and the plea deal would not have been so light.

And who was out drinking with Stallworth that night but the Jets’ Braylon Edwards, who was arrested for DUI a year later.

If the football field truly is nirvana for players, then the NFL must again re-examine its personal conduct policy and toughen suspension sanctions. The NFLPA must think beyond protecting players and protect those who could be injured or killed by them.

After his arrest, Smith bailed out of jail quickly and got to practice. There, coach Jim Harbaugh said his linebacker who had plowed into a tree a few hours earlier would practice and play on Sunday.

“He needs to go to work,” Harbaugh said.

In Smith’s case, the NFL workplace was the last place he needed to be.